Biblio

A recent proposed physical layer encryption technique uses an all-optical setup based on spatial light modulators to split two or more wavelength division multiplexed (WDM) signals in several spectral slices and to shuffle these slices. As a result, eavesdroppers aimed to recover information from a single target signal need to handle all the signals involved in the shuffling process. In this work, computer simulations are used to analyse the case where the shuffled signals propagate through different optical routes. From a security point of view, this is an interesting possibility because it obliges eavesdroppers to tap different optical fibres/ cables. On the other hand, each shuffled signal experiences different physical impairments and the deleterious consequences of these effects must be carefully investigated. Our results indicate that, in a metropolitan area network environment, penalties caused by attenuation and dispersion differences may be easily compensated with digital signal processing algorithms that are presently deployed.

In this paper, we propose a novel pseudo-random beamforming technique with beam selection for improving physical-layer security (PLS) in a downlink cellular network where consists of a base station (BS) with Ntantennas, NMSlegitimate mobile stations (MSs), and NEeavesdroppers. In the proposed technique, the BS generates multiple candidates of beamforming matrix each of which consists of orthogonal beamforming vectors in a pseudo-random manner. Each legitimate MS opportunistically feeds back the received signal-to-interference-and-noise ratio (SINR) value for all beamforming vectors to the BS. The BS transmits data to the legitimate MSs with the optimal beamforming matrix among multiple beam forming matrices that maximizes the secrecy sum-rate. Simulation results show that the proposed technique outperforms the conventional random beamforming technique in terms of the achievable secrecy sum-rate.

Friendly jamming is a physical layer security technique that utilizes extra available nodes to jam any eavesdroppers. This paper considers the use of additional available nodes as friendly jammers in order to improve the security performance of a route through a wireless area network. One of the unresolved technical challenges is the combining of security metrics with typical service quality metrics. In this context, this paper considers the problem of routing through a D2D network while jointly minimizing the secrecy outage probability (SOP) and connection outage probability (COP), using friendly jamming to improve the SOP of each link. The jamming powers are determined to place nulls at friendly receivers while maximizing the power to eavesdroppers. Then the route metrics are derived, and the problem is framed as a convex optimization problem. We also consider that not all network users equally value SOP and COP, and so introduce an auxiliary variable to tune the optimization between the two metrics.